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The Situation of Perceptions

In the most recent Sunday Boston Globe (Ideas section), Jonah Lehrer wrote a nice article — “Grape expectations: What wine can tell us about the nature of reality” — summarizing recent cognitive neuroscience research illustrating the power of expectations in shaping perceptions and experiences.

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Scientists at CalTech and Stanford recently published the results of a peculiar wine tasting. They provided people with cabernet sauvignons at various price points, with bottles ranging from $5 to $90. Although the tasters were told that all the wines were different, the scientists were in fact presenting the same wines at different prices.The subjects consistently reported that the more expensive wines tasted better, even when they were actually identical to cheaper wines.

The experiment was even more unusual because it was conducted inside a scanner–the drinks were sipped via a network of plastic tubes–that allowed the scientists to see how the subjects’ brains responded to each wine. When subjects were told they were getting a more expensive wine, they observed more activity in a part of the brain known to be involved in our experience of pleasure.

What they saw was the power of expectations. People expect expensive wines to taste better, and then their brains literally make it so. Wine lovers shouldn’t feel singled out: Antonio Rangel, the Caltech neuroeconomist who led the study, insists that he could have used a variety of items to get similar results, from bottled water to modern art.

Expectations have long been a topic of psychological research, and it’s well known that they affect how we react to events, or how we respond to medication. But in recent years, scientists have been intensively studying how expectations shape our direct experience of the world, what we taste, feel, and hear. The findings have been surprising– did you know that generic drugs can be less effective merely because they cost less?–and it’s now becoming clear just how pervasive the effects of expectation are.

The human brain, research suggests, isn’t built for objectivity. The brain doesn’t passively take in perceptions. Rather, brain regions involved in developing expectations can systematically alter the activity of areas involved in sensation. The cortex is “cooking the books,” adjusting its own inputs depending on what it expects.

Although much of this research has been done by scientists interested in marketing and consumer decisions, the work has broad implications. People assume that they perceive reality as it is, that our senses accurately record the outside world. Yet the science suggests that, in important ways, people experience reality not as it is, but as they expect it to be.

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Even our most primal bodily sensations, like pain, are vulnerable to the influence of expectation. Tor Wager, a neuroscientist at Columbia University, gave college students electrical shocks while they were stuck in a brain-scanning machine. Half of the people were then supplied with a placebo, . . . [and they] said the shocks were significantly less painful.

Wager then imaged the specific parts of the brain that controlled this psychological process. When people were told that they’d just received a pain-relieving cream, their prefrontal cortex, a brain area normally associated with rational thought, responded by inhibiting the activity of brain areas (like the insula) that normally respond to pain. However, when the same people were informed that the cream was “ineffective,” their prefrontal cortex went silent. Because people expected to experience less pain, they ended up experiencing less pain. Their predictions became self-fulfilling prophecies.

[The article then describes experiments by Baba Shiv, a neuroeconomist at Stanford, involving differently priced “energy” drinks.] [T]he people who paid discounted prices consistently solved fewer puzzles than the people who paid full price for the drinks, even though the drinks were identical.

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Why did the cheaper energy drink prove less effective? According to Shiv, a kind of placebo effect is at work. Since we expect cheaper goods to be less effective, they generally are less effective, even if they are identical to more expensive products. This is why brand-name aspirin works better than generic aspirin and why Coke tastes better than cheaper colas, even if most consumers can’t tell the difference in blind taste tests.

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One of the implications of Shiv’s experiment is that it’s possible to make a product more “effective” by increasing its price. A good marketing campaign can have a similar effect, as it instills consumers with lofty expectations about the quality of the product. . . .

* * *According to [Frederic] Brochet, [a cognitive psychologist at the University of Bordeaux,] the lesson . . . is that our experience is the end result of an elaborate interpretive process, in which the brain parses our sensations based upon our expectations. If we think a wine is red, or that a certain brand is better, then we will interpret our senses to preserve that belief. Such distortions are a fundamental feature of the brain.

Nevertheless, scientists insist that consumers can take steps to protect themselves from their expectations. . . .

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To read how, read the rest of Lehrer’s article here. Lehrer has a gem of a blog over at Frontal Cortex, which we’ve just added to our blogroll.